Silicon nanochannel field effect transistor (FET) nanosensors that utilize electrical detection mechanisms are a promising approach to the development of highly sensitive and label-free target species detection. Silicon nanochannels are well-suited for nanosensor applications due, in part, to the exceptional electrical properties and small dimensions. For instance, the small dimensions of silicon nanochannels allow them to have large surface to volume ratios that can result in relatively high electrical sensitivity. The relatively high electrical sensitivity allows silicon nanochannels to detect very low concentrations of the target species (e.g., a few molecules, a single molecule). FET nanosensors have numerous other benefits, such as high speed, low cost, and high yield manufacturing, amongst others, without sacrificing sensitivity. Moreover, top down manufacturing methods are able to leverage advantages in Complementary Metal Oxide Semiconductor technologies to make multiplexed FET nanosensor arrays.
Though FET nanosensors offer good sensitivity, specificity is a challenging issue. For example, the interaction of a target species with the detection element may be masked by less specific interactions of the detection element with other substances that have a greater abundance. Nanosensors must provide adequate sensitivity and specificity information to be used in applications such medical diagnostics, public health, epidemiologic studies, personalized medicine, monitoring, surveillance, agriculture, and defense industries. Accordingly, improved compositions and methods are needed.